LED grow tent heat issue

edwardnashton

New Member
Greetings folks,

I am having a heat issue with my recently purchased tent.

I have a 24x24x56 Growsun tent in a closet. inside I have a 400 watt (200 actual) Roleadro COB LED Light running full blast. Currently there are no plants inside.

For ventilation I have a 4" 100cfm inline fan angled to pull heat directly off of the led fans. the thermostat for my place is set on 72*. Tent has no air intake holes on the bottom (weird I know) so I used velcro to allow me to flip up the bottom of the tent door to allow for passive intake. I also have a 4 inch clip fan to circulate the air.

Even with the closet doors wide open and the fan in the room on full blast I am hitting temps in the high 80s within the first hour of the light kicking on. I am running it overnight as it is cooler then.

I am currently trying raising the light and keeping the door to the room open (not something I want to do as you can hear the fans outside of the room if you leave the door open) to see if that will help get me under 80*.

Is there anything I can do to help lower my temps? I know the light is a bit much for the space but cost wise it was the best deal I could find. Would cutting down to a lower wattage led help? I paid approx $100 for the light.

Thanks,
E. Nashton
 

hydra-glide

Well-Known Member
These nextLights run at no more than 104-degrees. Two clip fans keep the temps down to about 78, 24/7. I vent mine into my 10 ft. ceiling shop. This is the ONLY low-heat LED on the planet as far as I'm aware of. Buy from Henry, but wait until a 10% coupon shows up, like another 53 bucks off. Invest in quality, you've got 4-months living with any problems you've created. "Plan your grow, then grow your plan" - farmer
The pic is the Mini in a 48x48x79. My (7) plants are outgrowing the Mini.
The second pic is the Mega in a 5x5x80" PlanetHydro tent with LED vent-sock modifications. Set for 12/12 blooming when necessary. The magnificent seven are going in there, after I upcan to 7-gal. SmartPots today or tomorrow, then I'll give them light 24/7 using daylight and a 40W, T-12 shop light all night until morning. Then the gals either get drug outside or they get 12 hrs. of Mega LED light and 12-hrs. of non-growth under the 40W shop light that you see hanging low on yo-yo cords. (This allows me to re-capture the 10-days I'm losing bringing these gals out of early bloom..Yikes!)
When I need the 40W, I'll raise the LED mega panel and slide the 40W fixture, 2-3" above the canopy (under the non-lit LED), since the 40W is on separate ceiling rails than the LED .gro.3.JPG vnt.47.JPG
https://growlightcentral.com/products/nextlight-mini-led-grow-light
 

edwardnashton

New Member
Hey man,

Thanks for the reply. Unfortunately a $535 light is not really cost effective for such a small area. that is more than I spent on the grow light included so far.

I would love some other suggestions. Do you guys think dropping down to a 300 watt(most of them seem to be 135 to 150 watt actual) light would help take care of the heat issue? Thanks everyone.
 

majins

Well-Known Member
Either need to strongly vent the top of the tent to extract the heat out. Or build a water cooled cob setup and mount the radiator outside the tent.
 

Airwalker16

Well-Known Member
Greetings folks,

I am having a heat issue with my recently purchased tent.

I have a 24x24x56 Growsun tent in a closet. inside I have a 400 watt (200 actual) Roleadro COB LED Light running full blast. Currently there are no plants inside.

For ventilation I have a 4" 100cfm inline fan angled to pull heat directly off of the led fans. the thermostat for my place is set on 72*. Tent has no air intake holes on the bottom (weird I know) so I used velcro to allow me to flip up the bottom of the tent door to allow for passive intake. I also have a 4 inch clip fan to circulate the air.

Even with the closet doors wide open and the fan in the room on full blast I am hitting temps in the high 80s within the first hour of the light kicking on. I am running it overnight as it is cooler then.

I am currently trying raising the light and keeping the door to the room open (not something I want to do as you can hear the fans outside of the room if you leave the door open) to see if that will help get me under 80*.

Is there anything I can do to help lower my temps? I know the light is a bit much for the space but cost wise it was the best deal I could find. Would cutting down to a lower wattage led help? I paid approx $100 for the light.

Thanks,
E. Nashton
It's because you're not getting rid of that hot air. Like out the ceiling into the attic.
 

noodleman

Active Member
Airwalker is absolutely correct, you've got to get that heat out of the closet. I'm running up to 1,000 watts of LEDs in a 4x2x7 feet Gorilla tent in a closet and with the closet door open the temperatures stay in the low 80's. If I closed the door I'm certain the temps would go over 100.

Another point, from what I read LED grows can be warmer than HID because LEDs don't give off much radiant heat. It's important to keep HID grows cooler because in addition to the temperature measured in the tent there's a lot of radiant heat being emitted from the HID bulb that isn't measured by a temperature device not exposed to the direct rays of the lamp. So I wouldn't worry about temperatures in the low 80s anyway.
 

cannabisdreams

Well-Known Member
I have a 24x48x60" grow tent and a 600 watt (228W actual) LED. I have one 4" inline fan and one 100cfm computer fan pulling air out. I have a passive intake (no fan) and a small fan inside for circulation. My temps run right 82-85F and my plants are very happy/healthy. Is your inline fan actually in one of the top vent holes? You said you angled it so I wasn't sure how you did that if it was inside the vent hole. I would just add another vent fan, computer fans are cheap and the way they are designed makes it easy to attach to the tent vents.
20161030_211708.jpg 20161030_211708.jpg 20161030_211718.jpg 20161030_211727.jpg 20161030_211742.jpg 20161030_211825.jpg
 

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cannabisdreams

Well-Known Member
Also, I've grown under just 150 watts of HID with supplemental fluoros in the same space and temps were too high, I had to put the HID behind glass and dedicate an exhaust fan just to keep the temps below 90F. Like I said, I'm running at under 85F with the tent sealed up and running all day.
 

edwardnashton

New Member
Thanks for all the assistance everyone. I think I have this issue mostly resolved. I went and grabbed some chain that allowed me to hang my light higher and have purchase a 120cfm inline fan to replace my 100cfm fan. I think I might use the 100cfm fan as an active intake so I can light seal the bottom of the tent. As for the angled fan, it is in the vent hole in the top (one that is at the top of the tent but vents out the side). I do not have the fan strapped down so I am able to adjust where it is pointing. It was angled to pull air from the top of the tent. Now I have it aimed directly at the fans on the light. I also purchased some ducting. once the new fan comes in I plan on running ducting so the hot air is blowing out of the closet and cool air is being pulled from the other side of the closet. hopefully this will allow me to close the closet doors a bit more so it's less obvious what is going on in there.

Right now with both closet doors wide open I am only hitting 77-79 degrees.
 

cannabisdreams

Well-Known Member
What is your current temp with the tent closed up after an hour? In my opinion, as long as you have proper airflow, mid to high 80s is fine.
 

edwardnashton

New Member
I can not completely close the tent currently as the tent does not have a passive air intake at the bottom. I have to flip up part of the bottom of the door so fresh air can get in. right now I am hitting 77-79 with the closet doors open. I am hoping I can make the tent more light proof and allow for the doors to be shut a bit more by using a second fan and ducting to bring cool air in from the other side of the closet.
 

sL3xx

Well-Known Member
I just bought the same light in a 2x3x6 tent. see: http://imgur.com/a/MdTs0

It raises temps 8-10 degrees while on.
I had to mess with my intake/exhaust to get it around there. I have two of these with controllers and keep them on medium, I'd guess around 120-130 CFM tops:

VenTech IF4 4” Inline Duct Fan 190 CFM
https://www.amazon.com/gp/product/B005KMOJPK/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1


I have a carbon scrubber as well as a filter for my intake from Phresh. I have the exhaust controller set slightly higher to create negative pressure. It's doing a good job at keeping the temp down.

Increase your circulation. And you may need to keep your thermostat on 69 or 70 to bring it down a few degrees. Or turn off the heat in that room and use a space heater with a thermostat so you can have that room at a lower temp. More costly though.
 

ismann

Well-Known Member
I grow in a similar space, 24x24x48 inches with a Roleadro 600W (250W) LED.

100 CFM fan might not cut it. I would use that 4" fan as an intake at the bottom and get a 6" for an exhaust.

I use a 6" fan and scrubber and I feel that's pretty much the minimum for any size tent. They are also much quieter especially with a speed controller.

My temperatures are 73F outside the tent and do not go above 75F inside.
 

Olive Drab Green

Well-Known Member
I grow in a similar space, 24x24x48 inches with a Roleadro 600W (250W) LED.

100 CFM fan might not cut it. I would use that 4" fan as an intake at the bottom and get a 6" for an exhaust.

I use a 6" fan and scrubber and I feel that's pretty much the minimum for any size tent.

My temperatures are 73F outside the tent and do not go above 75F inside.
Not talking shit, but Roleandro was your first issue.
 

hydra-glide

Well-Known Member
I'm growing in a 5x5x80 tent, with my (2) vent clip-fans + (2) clip-fans on bases inside the tent blowing on the plants in 15-min. timed-increments, and with the tent door shut, the temps will climb to 84-degrees. I'm on 12/12 now and my daylight 12 is during the day, so I need to leave my tent unzipped and the top flaps pulled-back like lapels on a sport coat :) - and then my temps stay at 78-80, but no way could I do light dep. during the night with the tent closed. The plants would roast.
I hoisted both of the 40W shop lights up above the LED-Mega. Their there until they're needed, if needed. I'm getting (6) new clones for the 4x4x79 tent tomorrow and keep them under the LED-Mini, 24/7 for a while.
 

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cannabisdreams

Well-Known Member
Why does everybody think 80F is an issue? Its not the temp, its all about the airflow. My temps have always been in the mid 80s and I've never had a heat issue. Think about where these plants grow naturally... pretty much everywhere from Africa to Iceland... they do just fine with warmed temps as long as they have proper airflow. I think you might be overthinking it. This isn't rocket science, they are weeds.
 

cannabisdreams

Well-Known Member
OH and, just because it was made in China doesn't mean its crap. I bought a Chinese box, made sure it uses 5watt bridgelux leds and it works like a dream. Why spend three times the money? My buds look as fat as any other led grow I've seen out there. I'll know in a month how leds stack up against my older hps/flouro setup. Where is your evidence that Chinese boxes are crap? ... please don't cite other forums, no blind leading the blind responses please.
 

Gquebed

Well-Known Member
Why does everybody think 80F is an issue? Its not the temp, its all about the airflow. My temps have always been in the mid 80s and I've never had a heat issue. Think about where these plants grow naturally... pretty much everywhere from Africa to Iceland... they do just fine with warmed temps as long as they have proper airflow. I think you might be overthinking it. This isn't rocket science, they are weeds.
1) just because plants grow in hotter temps doesnt mean it is ideal.

2) most people are growing hybreds these days... and while the sativas may do better in higher heat the indicas generally do better in lower temps... so it makes sense that these hybreds land somewhere in between.

And while you think you think you may be doing fine in the low to mid 80s...maybe you could be doing better in the mid 70s? I used to be in the high 70s but i made adjustments because plenty of advanaced growers here said that such was ideal and found they were right. I got better yield and denser nugs...

There is a LOT of experienced guys on this site. They have made the errors and have since dialled in. Why not at least try their advice?
 
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